實體框架代碼優先：通過ID和類型的多個實體映射

Question

namespace Sample.Orders 
{ 
    public class Order : FullAuditedEntity<string> 
    { 
     [Column("OrderId")] 
     public override string Id { get; set; } 

     public long BillToAddressId { get; set; } 
     public virtual Address.BillToAddress BillTo { get; set; } 

     public string ShipToAddressId { get; set; } 
     public virtual Address.ShipToAddress ShipTo { get; set; } 
    } 
} 


namespace Sample.Shipments 
{ 
    public class Shipmen : FullAuditedEntity<string> 
    { 
     [Column("ShipmentId")] 
     public override string Id { get; set; } 

     public long AddressId { get; set; } 
     public virtual Address.ShipmentShipTo ShipTo { get; set; } 
    } 
} 

namespace Sample.Address 
{ 
    public abstract class Address : FullAuditedEntity<string> 
    { 
     public override string Id { get; set; } 
     public double Name { get; set; } 
     public string City { get; set; } 

     public string ParentId { get; set; } 
     public string AddressType { get; set; } 
    } 

    public class OrderBillTo : Address { } 
    public class OrderShipTo : Address { } 
    public class ShipmentShipTo : Address { } 
} 

數據庫：

訂單：

OrderId 
BillToAddressId 
ShipToAddressId 

地址：

Id 
Name 
City 
AddressType 

如何映射像這些

由字段OrderBillTo選擇從地址表的地址：的ParentId = {的OrderId}，地址類型= 'OrderBillTo'

由字段OrderShipTo選擇從地址表的地址：的ParentId = {的OrderId}，地址類型= 'OrderShipTo'

ShipmentShipTo通過字段選擇Address Address Address Address：ParentId = {AddressId}，AddressType ='ShipmentShipTo'

Thanks！

Answer 1

這不是EF設計用來處理的用例。它假定您有表和類之間的一對一映射。

這就是說，你真的需要Address的所有子類嗎？

Answer 2

用流利的API：

modelBuilder 
    .Entity<Order> 
    .HasOptional(order => order.BillTo) 
    .WithRequired(address => address.ParentId) 
    .HasForeignKey(order.BillToAddressId);  

modelBuilder 
    .Entity<Order> 
    .HasOptional(order => order.ShipTo) 
    .WithRequired(address => address.ParentId) 
    .HasForeignKey(order.ShipToAddressId);  

modelBuilder 
    .Entity<Shipment> 
    .HasOptional(order => order.ShipmentShipTo) 
    .WithRequired(address => address.ParentId) 
    .HasForeignKey(order.AddressId);